'72 wire harness run

[Larry D]

Hello, new to this forum; appreciate any help.
We are replacing the mid harness running the length of the frame (13A409 assy) on my son's '72 bronco. The previous owner just kind of had it tie wrapped in there with not much success. Any info on how it clips to the frame (what aftermarket clips to use) and detail of the run as it comes down from the LH side onto the frame and going rearwards would be appreciated.
Does the harness follow the fuel and brake line sandwiched between the frame and body mount? Along the frame does the harness stay below the fuel and brake line? Any pics would be appreciated. Not the most fan part of the Bronco but lights at the back end would be nice..

 

[DirtDonk]

Hey Larry D. Welcome to CB!
This sounds like you're doing a restoration, rather than a simple fix. Is that correct?

If so, I can only answer part of that right now, as most of the ones I've worked on lately have been modified. But yes, the general routing of the wires is along the fuel and brake lines. If I remember, they're not exactly together every inch, but in most places do follow the same general line.
Don't think the factory clips are being reproduced, but not sure what is best of closest to stock in this case. Pretty sure some of the members have had some luck with that though, so maybe they'll get you closer than I would.

Luckily though, my '71 is still sporting it's original rear harness. Not for long, but should still be intact behind the engine compartment. So if nobody has an answer for you on your '72 specifically, I can get a better description for you in the daylight. They should be pretty close, if not exactly the same, but there were definitely some minor variations between the two years in the overall harness layout.
Right now though, I'm "assuming" that the rear sections are going to be pretty much identical between the two years.

Good luck. More tomorrow if nobody else has the answer.

Paul

 

[Larry D]

Thanks DirkDonk, appreciate the help.
We have had the Bronc off the road for some time; pulled the engine out, fixing leaks. Not a real resto but want to get back to some sort of OE spec. Particularly interested if the harness runs to the outside of the front body mount inbetween the frame and body like the fuel and brake line. Also how the harness splits going to the brake pressure diff switch. We can make a harness run but it seems odd as rather then running parallel to fuel/brake lines it would lay over the brake and fuel lines which seems counter to what you would have thought an OE application would be. Thanks again.

 

[DirtDonk]

Yeah, but remember too, that back then this was just a simple utility vehicle running down an assembly line with different workers doing the job at different times and, though there were certainly expected methods and routing, there were bound to be times when, due to relatively few tie-down points, someone just decided to run it this way or that for expediency.
Things were designed a bit looser back then for "mere" trucks, with less thought to the finer details, vs just making it simple, fairly strong, fairly reliable for the few years it was expected to be doing work duty, and wire that was as small as they could spec it and still light the bulbs.

That's maybe oversimplifying things, but chalk it up to "manufacturing tolerances" and "assembly line variations" and you've got the very definition of a Bronco.

I'll go out now and take a quick look.

Paul

 

[DirtDonk]

Ok, sorry it took so long Larry. Got sidetracked on the way to your thread.

Here are some pics of the clamps and routing from just in front of the crossmember, where the brake warning light wires branch off.

 

[Larry D]

Paul,
Wow, great pics of exactly what we were looking for!! Those harness clips; I have seen them on early 70's F100's in the junk yard so they are available with some effort.
Thanks very much for your efforts and help to a Newbie.
Larry D

 

[DirtDonk]

Glad to help. And don't worry, you won't be a newbie for long. These things will suck you in until you don't recognize the real world out there anymore.
Just look at me. I just joined in November, and I'm already over 10,000 posts! ;D

Just kidding. Wrong November. But you get the point.
Enjoy.

Paul

 

[DirtDonk]

Oh, and good luck getting those clips out in good enough condition to re-use.
You might find yourself looking for a Plan-B after all.

Paul